Humidifier Philips 4000 series HU4210/03 Ultrasonic 3.5 L Black, 3 W, 100–240 V

The Philips 4000 series HU4210/03 ultrasonic humidifier is a compact household device designed to maintain comfortable indoor humidity in living rooms, bedrooms and nurseries. The unit features NanoCloud technology to generate fine, hygienic moisture, a 3.5 L top-fill water tank for extended run time and controls that include onboard buttons, smartphone app connectivity and voice assistant compatibility. Its black plastic housing, low power consumption and quiet sleep mode make it suitable for continuous home use.

Advantages

NanoCloud technology produces ultra-fine vapour that reduces bacterial emission compared with standard ultrasonic humidifiers and prevents white dust and wet stains on surfaces. The humidifier delivers up to 300 ml/h of moisture and can operate continuously for up to 21 hours on a full tank. Sleep mode lowers noise levels (around 6 dB) for night-time use, while the low power draw keeps energy use minimal. The device supports basic aromatherapy via a designated aroma compartment, offers easy top-fill access and uses a replaceable long-life filter for simplified maintenance.

Suitable for

• Homes: living rooms, bedrooms and nurseries
• People experiencing dry-air symptoms such as dry skin, dry throat or nasal congestion
• Rooms with wooden furniture or houseplants that benefit from stable humidity
• Users who require quiet night-time operation and remote control via app or voice assistants

Key specifications

• Humidification technology: NanoCloud evaporative/atomizing system
• Maximum moisture output: up to 300 ml/h
• Water tank capacity: 3.5 L
• Coverage: suitable for rooms up to approximately 44 m²
• Operating modes: 3 fan speeds, automatic mode, sleep mode (≈6 dB)
• Power consumption: low, up to approximately 3 W at highest setting
• Filter: replaceable long-life filter (typical lifespan up to 6 months)
• Water type: suitable for ordinary tap water
• Controls: onboard controls, smartphone app (Air+), voice assistant compatibility

How to use

Place the humidifier on a flat, level surface and fill the 3.5 L tank through the top-fill opening with tap water. Select the desired fan speed, automatic mode or sleep mode using the onboard controls or the smartphone app; voice commands can also be used if a compatible assistant is connected. For aromatherapy, add a few drops of an approved essential oil into the designated aroma compartment following the manufacturer guidance. Replace the filter at recommended intervals and clean the water tank and internal surfaces periodically to maintain hygienic operation.

Usage recommendations

Monitor room humidity with a hygrometer and aim for a comfortable range (commonly 40–60% relative humidity). Use the app to schedule operation and adjust settings remotely. Clean the tank and replace the filter regularly, and follow the manufacturer’s maintenance instructions when using tap water and aromatic oils to ensure safe, effective humidification.